In short: pregnancy is considered post-term from 42 completed weeks (294 days). The risks to the baby increase after 41 weeks. Most obstetricians offer induction of labor at 41-42 weeks - this reduces the risks and does not increase the frequency of cesarean sections.
What is a post-term pregnancy
The normal duration of pregnancy is 40 weeks (280 days) from the last menstrual period. Pregnancy is considered prolonged from 41 weeks and post-term from 42 completed weeks.
According to the WHO, about 10% of pregnancies last 42 weeks or more. In most cases, this is not a fetal pathology, but an individual feature. Nevertheless, after 41 weeks, the risks begin to increase - and doctors monitor the condition of the mother and baby more closely.
Possible causes
The exact causes of post-term pregnancy are unknown. Predisposing factors:
- Heredity (mother or grandmother also "walked around").
- First pregnancy.
- Male sex of the fetus (statistically more common).
- An error in the gestational age (the date of the last menstruation is not exactly known or the first ultrasound was performed late).
Clarification of the deadline
Before making decisions, the doctor must make sure that the gestational age is determined accurately. The gold standard is ultrasound in the first trimester (pregnancy, 11-14 weeks). If the first ultrasound was done later, the calculation error can be several days, and what seems to be "42 weeks" may turn out to be 40 + 5.
Risks of post-term pregnancy
After 42 weeks:
- The placenta "ages" - its ability to provide the fetus with oxygen and nutrients decreases.
- The risk of meconium staining of water (the child excretes meconium into the water) increases to 25-30%.
- The weight of the fetus can exceed 4 kg - the risk of complications during childbirth increases.
- The risk of fetal death (stillbirth) increases slightly, but statistically significantly.
Follow-up after 41 weeks
After 41 weeks, most obstetricians switch to more intensive monitoring:
- CTG (cardiotocography) 2-3 times a week to check the heartbeat and motor activity of the fetus.
- Ultrasound with Doppler and assessment of the amniotic fluid index.
- Counting the movements of the fetus by the mother is at least 10 movements in 2 hours.
Induction of labor in post-term pregnancy
Current recommendations from ACOG, NICE and the Ministry of Health of the Russian Federation recommend induction of labor at 41-42 weeks with a mature cervix. A large meta-analysis (Cochrane, 2018) found that induction in post-term pregnancy:
- reduces the risk of stillbirth;
- does not increase caesarean section rates;
- does not increase the frequency of other complications in the mother and baby.
Induction methods: mechanical (Foley catheter, dilators), medication (misoprostol, oxytocin). The choice is up to the doctor, taking into account the condition of the cervix and other factors.
What should a mother do
Up to 42 weeks:
- Do not stop counting the movements - make sure that the baby moves actively.
- Come for all routine examinations and CTG.
- Discuss the plan with the doctor: at what time and under what conditions induction will be offered.
- Know the signs of the onset of labor - sometimes labor begins on its own just a few hours before the planned induction.
When to see a doctor immediately
Call an ambulance or go to the hospital if:
- the baby has stopped moving or moving much less than usual;
- water has broken (especially green or brown);
- regular contractions began;
- Severe headache, visual impairment, edema are signs of preeclampsia.
Frequently Asked Questions
Is it possible to speed up labor on your own?
There is no method with proven effectiveness. Walking, sex, and nipple stimulation may have little effect on cervical readiness, but they do not induce labor "on command." In no case should you take any drugs without a doctor's prescription.
What if I refuse induction?
This is your right. However, you should be provided with comprehensive information about the risks of continuing follow-up after 42 weeks. If you refuse induction, monitoring should be very intensive.
Is a post-term pregnancy the fault of the mother?
No. It is not the result of any action or inaction. Condemning oneself is senseless and harmful. Your task is to make an informed decision together with the doctor about further tactics.
Conclusion
A post-term pregnancy requires close monitoring, but not panic. Modern medicine copes well with this situation. The main thing is to trust your doctor, come to all scheduled examinations and immediately respond to alarming signs.
Bibliography
- WHO. WHO recommendations for induction of labour. 2011. https://www.who.int/publications/i/item/9789241501156
- ACOG Practice Bulletin No. 146. Management of Late-Term and Postterm Pregnancies. Obstet Gynecol. 2014.
- Middleton P et al. Induction of labour at or beyond 37 weeks' gestation. Cochrane Database. 2018. https://pubmed.ncbi.nlm.nih.gov/30115809/
- NICE guideline NG207. Inducing labour. 2021. https://www.acog.org/womens-health/faqs/when-pregnancy-goes-past-your-due-date
- Ministry of Health of the Russian Federation. Clinical recommendations: Post-term pregnancy. 2022. https://cr.minzdrav.gov.ru/
This material is for informational purposes only and does not constitute medical advice and is not a substitute for medical advice. If a child's sleep is accompanied by alarming symptoms, a pronounced deterioration in health, problems with breathing, feeding or weight gain, it is necessary to consult a qualified medical specialist as soon as possible, and not rely only on information from the Internet.
